Even though not necessarily readily perceivable by consumers, commodity chemicals are ubiquitous in commercial channels. Many end-products incorporating commodity chemicals have specific cosmetic properties that are desired or required for consumer acceptance, and thus, commercial success. For example, many commodity chemicals, such as ethylene glycols or other glycols, are utilized in the production of fibers or foams that are subsequently utilized in the production of fabric or cushions later incorporated into articles introduced into the garment, transportation, sporting goods, household goods, etc. streams of commerce. Commercial acceptance and/or success of several, if not all, of these, may at least partially depend upon the ability to produce these articles in a specific color or color pattern.
In order to provide these chemicals with the initial color and/or dye integrity required by some customers, the chemicals typically must be of high purity, i.e., they are desirably substantially free of quantities of impurities that may impact the reproducible dyeability of the end product and/or impurities that absorb light in the visible region of the spectrum. As such, much effort has been focused on developing processes or methods for providing higher purity chemicals intended for use in such applications. Passing the chemicals through various filtration systems, e.g., comprising charcoal and/or ion exchange resins, can in some cases result in an improvement of the purity of the chemical, however, this method adds time and expense to the manufacturing process. Distillation has also been employed, and can result in separated fractions suitable for use in both high and low purity applications. Similar to filtration, however, distillation can add undesirable time and expense to the manufacturing process. Further, in some cases, distillation and filtration may not remove all, or enough of, the impurities to provide high purity chemicals.
Finally, some have attempted to control the formation of ultra-violet absorbing contaminants in such chemicals by adjusting the pH of the process used to produce them through acid addition. However, the addition of acids into many manufacturing processes can be problematic not only for the additional cost of the acid itself, but also because it can lower the pH to such an extent that damage can occur to processing equipment downstream from the acid addition. Further, efforts to control pH late in the manufacturing process may be thwarted by the presence of reaction products and by-products that influence the pH reading. In fact, if the pH is measured too late in the process, the offending by-products may have already been formed rendering any adjustments made to the pH superfluous. No methods known to Applicants have been provided that attempt to reduce the presence or formation of contaminants that absorb light in the visible portion of the spectrum, even though such contaminants can be, and often times are, just as objectionable, if not more objectionable, to the customers of such chemicals as UV absorbing contaminants.
Desirably, a process would be provided for producing low color glycols. The advantage of such a process would be amplified if it did not require the use of additional steps or equipment, and could be even further leveraged if it made use of reactants already utilized in the manufacturing process. Any such process would also desirably not include components capable of corroding or otherwise causing damage to existing equipment or creating additional safety issues.